immunize-missing-env-var

Q: What is a Claude Code skill and how does the immunize-missing-env-var skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. immunize-missing-env-var is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: General · Sub-category: general-misc · Last updated: 2026-05-21

Use when reading configuration from os.environ to check for missing values and raise a specific ConfigError instead of letting a raw KeyError escape.

Security AStatic scan found no risk patternsHow grading works ›

From the source SKILL.md

os.environ[...] is dict-style indexing. Missing keys raise KeyError with no context — the traceback shows an indexing line, not a message about which variable was expected or why the program needs it. In production logs, this reads as a mystery crash:

What this skill does

immunize-missing-env-var is a community-contributed Claude Code skill in the general-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/missing-env-var/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when reading configuration from os.environ to check for missing values and raise a specific ConfigError instead of letting a raw KeyError escape.

Who uses this skill

The immunize-missing-env-var Claude Code skill is built for Claude Code users and developers across all disciplines looking for general-purpose AI assistance. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 196,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/missing-env-var
curl -L https://claudskills.com/skills/missing-env-var/SKILL.md \
  -o ~/.claude/skills/missing-env-var/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/missing-env-var/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/missing-env-var/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\missing-env-var\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the immunize-missing-env-var Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/missing-env-var/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the immunize-missing-env-var skill do?

Use when reading configuration from os.environ to check for missing values and raise a specific ConfigError instead of letting a raw KeyError escape.

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the immunize-missing-env-var skill?

Use immunize-missing-env-var when your Claude Code task falls under the General category — specifically in the general misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use immunize-missing-env-var" or describe the task and let Claude pick). Browse related skills at /category/general/.

What is a Claude Code skill and how does the immunize-missing-env-var skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. immunize-missing-env-var is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at /learn/what-is-a-claude-skill/.

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

ClaudSkills. (2026). immunize-missing-env-var [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/missing-env-var/

BibTeX

@misc{missing-env-var-2026,
  author    = {ClaudSkills},
  title     = {immunize-missing-env-var [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/missing-env-var/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/missing-env-var.svg)](https://claudskills.com/skills/missing-env-var/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-09-28 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/missing-env-var/#security)

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Browse all General skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

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